Safety against brittle fracture of the reactor pressure vessel in the nuclear power plant Obrigheim

Obrigheim, the first pressurized light water reactor built in Germany, oper ates with a nominal power of 357 MW. Since the beginnings of electricity pr oduction in 1968 the nuclear power plant Obrigheim (KWO) has proved to be a reliable and safe operation with a high availability, in terms of time, of 81.4% over 29 years. The reactor pressure vessel could be qualified for fu ture operation by means of inservice inspections, irradiation programs, flu ence calculations, nondestructive testing, investigations of pressurized th ermal shock (PTS) conditions and by implementation of technical improvement s for operation and maintenance. The main steps of the final licensing proc edure, for the qualification of the reactor pressure vessel relative to irr adiation embrittlement and safety against brittle fracture under pressurize d thermal shock conditions, are presented as a summary of investigations an d experiences over more than 20 years. (C) 2000 Elsevier Science S.A. All r ights reserved.